/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.rule;

import java.util.HashMap;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.rule.pattern.NodeTypePattern;

/**
 * <p> <code>RuleManager</code> manages a set of rules such that a rule can be
 * found for a given DOM4J Node using the XSLT processing model. </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public class RuleManager
{
   /** Map of modes indexed by mode */
   private HashMap modes = new HashMap();

   /**
    * A counter so that rules can be ordered by the order in which they were
    * added to the rule base
    */
   private int appearenceCount;

   /** Holds value of property valueOfAction. */
   private Action valueOfAction;

   public RuleManager()
   {
   }

   /**
    * DOCUMENT ME!
    * 
    * @param modeName DOCUMENT ME!
    * 
    * @return the Mode instance for the given mode name. If one does not exist
    *         then it will be created.
    */
   public Mode getMode(String modeName)
   {
      Mode mode = (Mode) modes.get(modeName);

      if(mode == null)
      {
         mode = createMode();
         modes.put(modeName, mode);
      }

      return mode;
   }

   public void addRule(Rule rule)
   {
      rule.setAppearenceCount(++appearenceCount);

      Mode mode = getMode(rule.getMode());
      Rule[] childRules = rule.getUnionRules();

      if(childRules != null)
      {
         for(int i = 0, size = childRules.length; i < size; i++)
         {
            mode.addRule(childRules[i]);
         }
      }
      else
      {
         mode.addRule(rule);
      }
   }

   public void removeRule(Rule rule)
   {
      Mode mode = getMode(rule.getMode());
      Rule[] childRules = rule.getUnionRules();

      if(childRules != null)
      {
         for(int i = 0, size = childRules.length; i < size; i++)
         {
            mode.removeRule(childRules[i]);
         }
      }
      else
      {
         mode.removeRule(rule);
      }
   }

   /**
    * Performs an XSLT processing model match for the rule which matches the
    * given Node the best.
    * 
    * @param modeName is the name of the mode associated with the rule if any
    * @param node is the DOM4J Node to match against
    * 
    * @return the matching Rule or no rule if none matched
    */
   public Rule getMatchingRule(String modeName, Node node)
   {
      Mode mode = (Mode) modes.get(modeName);

      if(mode != null)
      {
         return mode.getMatchingRule(node);
      }
      else
      {
         System.out.println("Warning: No Mode for mode: " + mode);

         return null;
      }
   }

   public void clear()
   {
      modes.clear();
      appearenceCount = 0;
   }

   // Properties
   // -------------------------------------------------------------------------

   /**
    * DOCUMENT ME!
    * 
    * @return the default value-of action which is used in the default rules for
    *         the pattern "text()|&#64;"
    */
   public Action getValueOfAction()
   {
      return valueOfAction;
   }

   /**
    * Sets the default value-of action which is used in the default rules for
    * the pattern "text()|&#64;"
    * 
    * @param valueOfAction DOCUMENT ME!
    */
   public void setValueOfAction(Action valueOfAction)
   {
      this.valueOfAction = valueOfAction;
   }

   // Implementation methods
   // -------------------------------------------------------------------------

   /**
    * A factory method to return a new {@link Mode}instance which should add
    * the necessary default rules
    * 
    * @return DOCUMENT ME!
    */
   protected Mode createMode()
   {
      Mode mode = new Mode();
      addDefaultRules(mode);

      return mode;
   }

   /**
    * Adds the default stylesheet rules to the given {@link Mode}instance
    * 
    * @param mode DOCUMENT ME!
    */
   protected void addDefaultRules(final Mode mode)
   {
      // add an apply templates rule
      Action applyTemplates = new Action()
         {
            public void run(Node node) throws Exception
            {
               if(node instanceof Element)
               {
                  mode.applyTemplates((Element) node);
               }
               else if(node instanceof Document)
               {
                  mode.applyTemplates((Document) node);
               }
            }
         };

      Action valueOf = getValueOfAction();

      addDefaultRule(mode, NodeTypePattern.ANY_DOCUMENT, applyTemplates);
      addDefaultRule(mode, NodeTypePattern.ANY_ELEMENT, applyTemplates);

      if(valueOf != null)
      {
         addDefaultRule(mode, NodeTypePattern.ANY_ATTRIBUTE, valueOf);
         addDefaultRule(mode, NodeTypePattern.ANY_TEXT, valueOf);
      }
   }

   protected void addDefaultRule(Mode mode, Pattern pattern, Action action)
   {
      Rule rule = createDefaultRule(pattern, action);
      mode.addRule(rule);
   }

   protected Rule createDefaultRule(Pattern pattern, Action action)
   {
      Rule rule = new Rule(pattern, action);
      rule.setImportPrecedence(-1);

      return rule;
   }
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
